Regex extract

Supported in: Batch, Streaming

Extracts the specified group from a regex. Returns empty string when no match is found.

Expression categories: Regex, String

Declared arguments

• Expression: The expression to extract from.
  Expression<String>
• Group: The group to extract from the regex match.
  Literal<Integer>
• Pattern: The regex pattern to match.
  Expression<String>

Output type: String

Examples

Example 1: Base case

Description: Extract the first two initials from the first match.

Argument values:

• Expression: MT-112, XB-967
• Group: 1
• Pattern: (\w\w)(-)

Output: MT

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Example 2: Base case

Argument values:

• Expression: MT-112, XB-967
• Group: 0
• Pattern: NOT_FOUND

Output: empty string

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Example 3: Base case

Argument values:

• Expression: zzzzhello hellozzzz
• Group: 1
• Pattern: (hello) \1

Output: hello

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Example 4: Base case

Argument values:

• Expression: helloworld
• Group: 1
• Pattern: (\w+)(?=world)

Output: hello

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Example 5: Null case

Description: Null inputs give null outputs.

Argument values:

• Expression: null
• Group: 1
• Pattern: (\w\w)(-)

Output: null

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